Familial adenomatous polyposis associated with gastrointestinal stromal tumor: report of a case.

Desmoid tumors are one of the most common extracolonic manifestations of the familial adenomatous polyposis. However, other soft tissue tumors are seen rarely in patients with familial adenomatous polyposis, including gastrointestinal stromal tumor. There is only one case reported in the literature. We describe a 29-year-old female who developed ileal malignant gastrointestinal stromal tumor 15 months after proctocolectomy for familial adenomatous polyposis, with a review of the literature focusing on sarcomas arising in this inherited disease. We suggest that the rare occurrence of gastrointestinal stromal tumor in familial adenomatous polyposis does not exclude their consideration in the differential diagnosis of extracolonic manifestations of the disease.